In the field of power measurement, metering, and management, a need exists to have the capability to reduce large amounts of data at remote sites over long periods of time and to transmit that reduced data via communication lines to a central site or, alternatively, to store the reduced data at the site for later analysis. Problems associated with having the capability for such data reduction at remote sites include both how to achieve the flexibility to perform different types of data reduction and how to maintain the reliability and integrity of the devices or programs performing the data reduction. Such flexibility generally requires a programming capability, typically obtained by employing programmable devices; however, in the environment of power measurement, metering and management, remote locations or sites are particularly vulnerable to data collection and data reduction problems from power supply anamolies, ionized radiation, and other device environment-related problems that may affect devices providing such programmability, such as random access memories. Likewise, because this data collection and reduction may be performed over long periods of time, including years, such errors may not be discovered until long after any "damage," in terms of the production of meaningless or useless data, has already taken place.
One approach would employ read only memories (ROM's) at such remote sites. However, such an approach limits flexibility and may introduce additional expense because typically a different ROM is necessary for each different program. Another approach would attempt to verify the integrity of the stored electrical signals. One known technique for verifying such stored electrical signals is a "checksum." Such a technique has several difficulties, however. First, it will not necessarily permit a complete verification because errors may offset each other. Second, it may be time consuming or burdensome to execute regularly or periodically. Thus, a need exists for a method or system for maintaining the integrity and reliability of electrical signals stored in various memory locations of a programmable memory storage device located at a remote site.